base/sys_info_android.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/sys_info.h"
   6
   7 #include <sys/system_properties.h>
   8
   9 #include "base/android/sys_utils.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/logging.h"
  12 #include "base/strings/string_number_conversions.h"
  13 #include "base/strings/string_piece.h"
  14 #include "base/strings/stringprintf.h"
  15 #include "base/sys_info_internal.h"
  16
  17 namespace {
  18
  19 // Default version of Android to fall back to when actual version numbers
  20 // cannot be acquired. Use the latest Android release with a higher bug fix
  21 // version to avoid unnecessarily comparison errors with the latest release.
  22 // This should be manually kept up-to-date on each Android release.
  23 const int kDefaultAndroidMajorVersion = 4;
  24 const int kDefaultAndroidMinorVersion = 4;
  25 const int kDefaultAndroidBugfixVersion = 99;
  26
  27 // Parse out the OS version numbers from the system properties.
  28 void ParseOSVersionNumbers(const char* os_version_str,
  29                            int32 *major_version,
  30                            int32 *minor_version,
  31                            int32 *bugfix_version) {
  32   if (os_version_str[0]) {
  33     // Try to parse out the version numbers from the string.
  34     int num_read = sscanf(os_version_str, "%d.%d.%d", major_version,
  35                           minor_version, bugfix_version);
  36
  37     if (num_read > 0) {
  38       // If we don't have a full set of version numbers, make the extras 0.
  39       if (num_read < 2) *minor_version = 0;
  40       if (num_read < 3) *bugfix_version = 0;
  41       return;
  42     }
  43   }
  44
  45   // For some reason, we couldn't parse the version number string.
  46   *major_version = kDefaultAndroidMajorVersion;
  47   *minor_version = kDefaultAndroidMinorVersion;
  48   *bugfix_version = kDefaultAndroidBugfixVersion;
  49 }
  50
  51 // Parses a system property (specified with unit 'k','m' or 'g').
  52 // Returns a value in bytes.
  53 // Returns -1 if the string could not be parsed.
  54 int64 ParseSystemPropertyBytes(const base::StringPiece& str) {
  55   const int64 KB = 1024;
  56   const int64 MB = 1024 * KB;
  57   const int64 GB = 1024 * MB;
  58   if (str.size() == 0u)
  59     return -1;
  60   int64 unit_multiplier = 1;
  61   size_t length = str.size();
  62   if (str[length - 1] == 'k') {
  63     unit_multiplier = KB;
  64     length--;
  65   } else if (str[length - 1] == 'm') {
  66     unit_multiplier = MB;
  67     length--;
  68   } else if (str[length - 1] == 'g') {
  69     unit_multiplier = GB;
  70     length--;
  71   }
  72   int64 result = 0;
  73   bool parsed = base::StringToInt64(str.substr(0, length), &result);
  74   bool negative = result <= 0;
  75   bool overflow = result >= std::numeric_limits<int64>::max() / unit_multiplier;
  76   if (!parsed || negative || overflow)
  77     return -1;
  78   return result * unit_multiplier;
  79 }
  80
  81 int GetDalvikHeapSizeMB() {
  82   char heap_size_str[PROP_VALUE_MAX];
  83   __system_property_get("dalvik.vm.heapsize", heap_size_str);
  84   // dalvik.vm.heapsize property is writable by a root user.
  85   // Clamp it to reasonable range as a sanity check,
  86   // a typical android device will never have less than 48MB.
  87   const int64 MB = 1024 * 1024;
  88   int64 result = ParseSystemPropertyBytes(heap_size_str);
  89   if (result == -1) {
  90      // We should consider not exposing these values if they are not reliable.
  91      LOG(ERROR) << "Can't parse dalvik.vm.heapsize: " << heap_size_str;
  92      result = base::SysInfo::AmountOfPhysicalMemoryMB() / 3;
  93   }
  94   result = std::min<int64>(std::max<int64>(32 * MB, result), 1024 * MB) / MB;
  95   return static_cast<int>(result);
  96 }
  97
  98 int GetDalvikHeapGrowthLimitMB() {
  99   char heap_size_str[PROP_VALUE_MAX];
 100   __system_property_get("dalvik.vm.heapgrowthlimit", heap_size_str);
 101   // dalvik.vm.heapgrowthlimit property is writable by a root user.
 102   // Clamp it to reasonable range as a sanity check,
 103   // a typical android device will never have less than 24MB.
 104   const int64 MB = 1024 * 1024;
 105   int64 result = ParseSystemPropertyBytes(heap_size_str);
 106   if (result == -1) {
 107      // We should consider not exposing these values if they are not reliable.
 108      LOG(ERROR) << "Can't parse dalvik.vm.heapgrowthlimit: " << heap_size_str;
 109      result = base::SysInfo::AmountOfPhysicalMemoryMB() / 6;
 110   }
 111   result = std::min<int64>(std::max<int64>(16 * MB, result), 512 * MB) / MB;
 112   return static_cast<int>(result);
 113 }
 114
 115 }  // anonymous namespace
 116
 117 namespace base {
 118
 119 std::string SysInfo::OperatingSystemName() {
 120   return "Android";
 121 }
 122
 123 std::string SysInfo::GetAndroidBuildCodename() {
 124   char os_version_codename_str[PROP_VALUE_MAX];
 125   __system_property_get("ro.build.version.codename", os_version_codename_str);
 126   return std::string(os_version_codename_str);
 127 }
 128
 129 std::string SysInfo::GetAndroidBuildID() {
 130   char os_build_id_str[PROP_VALUE_MAX];
 131   __system_property_get("ro.build.id", os_build_id_str);
 132   return std::string(os_build_id_str);
 133 }
 134
 135 std::string SysInfo::GetDeviceName() {
 136   char device_model_str[PROP_VALUE_MAX];
 137   __system_property_get("ro.product.model", device_model_str);
 138   return std::string(device_model_str);
 139 }
 140
 141 std::string SysInfo::OperatingSystemVersion() {
 142   int32 major, minor, bugfix;
 143   OperatingSystemVersionNumbers(&major, &minor, &bugfix);
 144   return StringPrintf("%d.%d.%d", major, minor, bugfix);
 145 }
 146
 147 void SysInfo::OperatingSystemVersionNumbers(int32* major_version,
 148                                             int32* minor_version,
 149                                             int32* bugfix_version) {
 150   // Read the version number string out from the properties.
 151   char os_version_str[PROP_VALUE_MAX];
 152   __system_property_get("ro.build.version.release", os_version_str);
 153
 154   // Parse out the numbers.
 155   ParseOSVersionNumbers(os_version_str, major_version, minor_version,
 156                         bugfix_version);
 157 }
 158
 159 int SysInfo::DalvikHeapSizeMB() {
 160   static int heap_size = GetDalvikHeapSizeMB();
 161   return heap_size;
 162 }
 163
 164 int SysInfo::DalvikHeapGrowthLimitMB() {
 165   static int heap_growth_limit = GetDalvikHeapGrowthLimitMB();
 166   return heap_growth_limit;
 167 }
 168
 169 static base::LazyInstance<
 170     base::internal::LazySysInfoValue<bool,
 171         android::SysUtils::IsLowEndDeviceFromJni> >::Leaky
 172     g_lazy_low_end_device = LAZY_INSTANCE_INITIALIZER;
 173
 174 bool SysInfo::IsLowEndDevice() {
 175   return g_lazy_low_end_device.Get().value();
 176 }
 177
 178
 179 }  // namespace base